Cantilevered x-ray CT system for multi-axis imaging

Abstract

A multi-axis imaging system comprising an imaging gantry with an imaging axis extending through a bore of the imaging gantry, a support column that supports the imaging gantry on one side of the gantry in a cantilevered manner, and a base that supports the imaging gantry and the support column. The imaging system including a first drive mechanism that translates the gantry in a vertical direction relative to the support column and the base, a second drive mechanism that rotates the gantry with respect to the support column between a first orientation where the imaging axis of the imaging gantry extends in a vertical direction parallel to the support column and a second orientation where the imaging axis of the gantry extends in a horizontal direction parallel with the base, and a third drive mechanism that translates the support column and the gantry in a horizontal direction along the base.

What is claimed is: 
     
       1. A multi-axis imaging system, comprising:
 a patient support including a drive system for moving the patient support between a plurality of positions; 
 an imaging gantry with an imaging axis extending through a bore of the imaging gantry; 
 a support column that supports the imaging gantry on one side of the gantry in a cantilevered manner; 
 a base that supports the imaging gantry and the support column; 
 a plurality of drive mechanisms for moving the gantry in at least three degrees of freedom including;
 a first drive mechanism that translates the gantry in a vertical direction relative to the support column and the base; 
 a second drive mechanism that rotates the gantry with respect to the support column between a first orientation where the imaging axis of the imaging gantry extends in a vertical direction parallel to the support column and a second orientation where the imaging axis of the gantry extends in a horizontal direction parallel with the base; and 
 a third drive mechanism that translates the support column and the gantry in a horizontal direction along the base; 
 
 a control system that receives data from the patient support, data indicating a position and a tilt angle of the patient support, and sends control signals to one or more of the plurality of drive mechanisms to cause the gantry to move and position a center of the bore of the gantry axially with the patient support in response to the data received from the control system. 
 
     
     
       2. The multi-axis imaging system of  claim 1 , wherein the patient support moves between a horizontal position where a longitudinal axis of the patient support parallel to the base; and
 a vertical position where the longitudinal axis of the patient support is perpendicular to the base; and
 the gantry moves with the patient support between the horizontal position and the vertical position, axially aligning the bore of the gantry with the longitudinal axis of the patient support. 
 
 
     
     
       3. The multi-axis imaging system of  claim 2 , wherein the patient support moves to a third position where the patient support is in an angled position, positioning the longitudinal axis of the patient at an angle greater than 0 degrees and less than 90 degrees relative to the base. 
     
     
       4. The multi-axis imaging system of  claim 2 , wherein the second drive mechanism is configured to rotate the gantry between a first orientation, wherein an imaging axis extending through a bore of the gantry extends in a vertical direction, and a second orientation, wherein an imaging axis extending through the bore of the gantry extends in a horizontal direction. 
     
     
       5. The multi-axis imaging system of  claim 1 , wherein the first drive mechanism is a non-backdrivable drive mechanism including a motor geared into a lead screw that extends along a length of the support column, and a carriage connected with the gantry has a nut fixed thereto that engages with the lead screw such that a rotation of the lead screw drives a translation of the carriage and the gantry in a vertical direction relative to the support column, the lead screw and the nut are free from backdriving under load. 
     
     
       6. The multi-axis imaging system of  claim 5 , wherein the support column comprises a plurality of rails extending parallel to one another over a surface of the support column and the gantry is mounted to a carriage having bearing elements that engage with the rails to displace the gantry in a vertical direction relative to the support column. 
     
     
       7. The multi-axis imaging system of  claim 5 , wherein the first drive mechanism comprises a motor geared into a threaded shaft that extends along the length of the support column, and the carriage has a nut fixed thereto that engages with the threaded shaft such that a rotation of the threaded shaft drives a translation of the carriage and the gantry in a vertical direction relative to the support column. 
     
     
       8. The multi-axis imaging system of  claim 7 , wherein the second drive mechanism is mounted to the carriage. 
     
     
       9. The multi-axis imaging system of  claim 8 , wherein the second drive mechanism comprises a motor mechanically coupled to a first race of a rotary bearing such that the motor drives the rotation of the first race relative to a second race of the rotary bearing, and the first race is attached to the gantry and the second race is attached to the carriage. 
     
     
       10. The multi-axis imaging system of  claim 9 , wherein the motor drives a drive wheel that engages with a drive belt that extends over a surface of the first race and drives the rotation of the first race relative to the second race. 
     
     
       11. The multi-axis imaging system of  claim 10 , wherein opposing ends of the drive belt are attached to the first race. 
     
     
       12. The multi-axis imaging system of  claim 5 , wherein the base comprises at least one rail extending along a length of the base, and the support column is mounted to a platform having at least one bearing element that engages with the at least one rail to displace the support column and the gantry in a horizontal direction with respect to the base. 
     
     
       13. The multi-axis imaging system of  claim 12 , wherein the third drive mechanism comprises a drive belt extending along the length of the base parallel to the at least one rail and a motor mounted to the platform that drives a drive wheel that engages with the drive belt to drive the displacement of the support column and the gantry. 
     
     
       14. The multi-axis imaging system of  claim 13 , wherein the base comprises at least one cover attached to the platform and/or the support column that extends from and retracts into a housing based on the translation of the support column relative to the base. 
     
     
       15. A method of operating a multi-axis imaging system comprising a moveable imaging gantry attached to a support column that supports the imaging gantry on one side of the gantry in a cantilevered manner, a base that supports the imaging gantry and the support column, a first drive mechanism that translates the gantry in a vertical direction relative to the support column and the base, a second drive mechanism that rotates the gantry with respect to the support column; and a third drive mechanism that translates the support column and the gantry in a horizontal direction along the base, the method comprising:
 receiving, from a control system of a moveable patient support, data indicating a position and a tilt angle of the patient support; and 
 sending control signals to one or more drive mechanisms of the multi-axis imaging system to cause the gantry to move in one or more degrees of freedom to maintain a bore of the gantry in a spaced away relationship from the patient support, the bore of the gantry aligned with the patient support in response to the data received from the control system of the moveable patient support; 
 wherein the gantry is moveable by translating in a first direction and in a second direction and by rotating with respect to an axis extending in a third direction, where the first, second and third directions are mutually orthogonal; 
 wherein the gantry is axially aligned with the patient support by a distance sufficient to prevent a surface of the gantry from colliding with the patient support or a patient supported thereon while the patient support is moving. 
 
     
     
       16. The method of  claim 15 , wherein the second drive mechanism is configured to rotate the gantry between a first orientation, wherein an imaging axis extending through the bore of the gantry extends in a vertical direction, and a second orientation, wherein an imaging axis extending through the bore of the gantry extends in a horizontal direction. 
     
     
       17. The method of  claim 16  further comprising: scanning with the gantry in a first position where the patient support is in a horizontal position, positioning a longitudinal axis of the patient support parallel to the base; and
 scanning with the gantry in a second position where the patient support is in a vertical position, position the longitudinal axis of the patient support perpendicular to the base. 
 
     
     
       18. The method of  claim 17  further comprising scanning with the gantry in a third position where the patient support is in an angled position, positioning the longitudinal axis of the patient at an angle greater than 0 degrees and less than 90 degrees relative to the base.